# Diagrams Notepad 3 vs Zen Pi

The clearest difference is rating: Zen Pi at 5.0 against Diagrams Notepad 3's 3.5. Zen Pi also leads on in-app purchases (none vs 1). Diagrams Notepad 3's advantage is update cadence (monthly vs every 7 months) and ratings volume (52 vs 2). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Diagrams Notepad 3 sells 1 one-off in-app purchase. Zen Pi asks for nothing beyond the download.

Zen Pi holds the better App Store score, 5.0 against 3.5. That said, the two scores are not equally well evidenced: Diagrams Notepad 3 has 52 ratings behind it against 2, so its average is the more settled of the two.

Diagrams Notepad 3 ships an update monthly, Zen Pi every 7 months. The most recent releases landed on November 2, 2026 and October 30, 2026 respectively.

## The numbers

| Metric | Diagrams Notepad 3 | Zen Pi |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [3.5 (52 ratings)](https://appshunter.io/ios/app/diagrams-notepad-3/id1387425355/reviews) | **[5.0 (2 ratings)](https://appshunter.io/ios/app/zen-pi/id6737859326/reviews)** |
| Number of ratings | **52** | 2 |
| Positive reviews | 39.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | **Monthly** | Every 7 months |
| Monetization | Free with in-app purchases | **Free** |
| Size | 29 MB | 1 MB |
| Requires iOS | **15.0** | 16.6 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, Mac |
| Age rating | 4+ | 17+ |
| Developer | [sunata UG (haftungsbeschraenkt)](https://appshunter.io/developer/1387425354) | [Christopher Huffaker](https://appshunter.io/developer/1778117639) |

## What reviewers say

### Diagrams Notepad 3

[App page](https://appshunter.io/ios/app/diagrams-notepad-3/id1387425355)

Create and sync diagrams, flowcharts, and mind maps across iPhone, iPad, and Mac. Supports Apple Pencil for drawing and offers collaboration features. Export in various formats.

**Highlights:** Cross-device sync via iCloud, Vector-based shapes and connectors, Apple Pencil support, Diagram sharing and collaboration, Export to PDF, PNG, JPEG, Unlimited diagram size

**Features:** Family Sharing

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlimited number of diagrams | $22.99 | one-time |


### Zen Pi

[App page](https://appshunter.io/ios/app/zen-pi/id6737859326)

This app helps you manage your time by breaking it down into weekly and daily increments. It tracks time remaining in seconds for both the day and the year, and offers a daily astrological outlook.

**Highlights:** Weekly time management, Daily time tracking in seconds, Time remaining in year calculation, Daily astrological outlook, Productivity enhancement

**Features:** Vision Pro support

**In-app purchases:** none


## Frequently asked questions

### Is Diagrams Notepad 3 free?

Diagrams Notepad 3 is free to download, with in-app purchases available.

### Is Zen Pi free?

Zen Pi is free to download, with no in-app purchases.

### Which has better reviews, Diagrams Notepad 3 or Zen Pi?

Zen Pi is rated higher. Diagrams Notepad 3 averages 3.5 out of 5 from 52 ratings, while Zen Pi averages 5.0 from 2 ratings.

### Do Diagrams Notepad 3 or Zen Pi have ads?

Neither Diagrams Notepad 3 nor Zen Pi shows ads.

### Which is updated more often, Diagrams Notepad 3 or Zen Pi?

Diagrams Notepad 3 ships an update monthly, and Zen Pi every 7 months. Most recently, Diagrams Notepad 3 was updated on November 2, 2026 and Zen Pi on October 30, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*